Process of making spelter.



Patented August 2, 1904.

PATENT OFFICE.

OSKAR NAGEL, OF HAHBORN, GERMANY.

PROCESS OF MAKING SPELTER.

SPECIFICATION forming part of Letters Patent No. 766,279, dated August2, 1904.

Application filed January 12, 1903.

To all whom it TYLH/Z/ concern:

Be it known that I, OSKAR NAGEL, a citizen of the United States,residing at Hamborn, Rheinland, (urermany, have invented a certain newand useful Process of Making Spelter, of which the following is aspecification.

My invention relates to an improved process for making spelter, designedespecially to be'carried out in a blast-furnace, with consequent economyin the cost of production; but the invention is not limited to themaking of spelter in such an apparatus.

In my Patent No. 699,969, of May 13, 1902, I describe a process ofproducing spelter by reducing zinc oxid in a blast-furnace or similarapparatus by means of water gas. In that patent I call attention to thefact that previous experiments were unsuccessful on account of the greatquantity of combustiongases and nitrogen in the zinc atmosphere whichprevented the liquid condensation, but resulted only in the productionof zinc-dustI As a result of further experimenting along the linesindicated by me in that patent I have found that hydrocarbons in gaseousor gasitied condition, including, of course, coal-gas and natural gas,are equal and sometimes superior to water-gas for carrying the processinto effect. Natural gas containing from eighty-five to ninety per cent.of methane (CH!) is especially advantageous, as the concentration ofzinc-vapors obtained is nearly twice as large as with water-gas. Thissuperior result can be theoretically explained by the fact that onemolecule of water-gas (GO-kHz) combines only with two atoms of oxygen,but one molecule of methane combines with four atoms of oxygen.Furthermore, the coeflicient of mo lecular friction of methane is onlyabout half of that of water-gas, which fact explains the easycondensation of zinc in a methane atmosphere. On account of thesesuperior qualities of methane as compared to water-gas for the purpose aconsiderable quantity of nitrogen may become added to methane withoutaffecting the reducing capacity of the latter as compared to water-gas.I find, for instance,

Serial No. 138,732. (No specimens.)

that a mixture of ninety per cent, methane and ten per cent. nitrogen issuperior to water-gas and that a mixture of eighty-five per cent.methane and fifteen per cent. nitrogen is about equal to water-gas. Afurther increase of nitrogen in the natural gas makes it of courseinferior to water-gas. As natural gas with eighty-five to ninety percent. methane and two to fifteen per cent. of nitrogen occurs veryfrequently, (containing sometimes 0.20 per cent.sulfuretedhydrogen,which,however, is not injurious at the-heat of the zincreduction,) I am enabled to always utilize a cheap substitute for thewater-gas and which, in fact, as I have indicated, is often verysuperior to the latter. Besides methane, natural gas, or coal-gas anyother gaseous or gasified hydrocarbons or mixtures of these withwatergas can be used for my purpose, as in the heat they act alike. Theatmosphere of all these hydrocarbons in gaseous or gasified form iseminently reducing and allows of an easy condensation to liquid metal.

In the use of the process with a gaseous or gasified hydrocarbon, asindicated, 1 proceed in practically the same way as I have described inmy said patent in connection with watergas. By passing such heatedhydrocarbons through a Zinc ore or a mixture of ore with from ten tofifteen per cent. of coal the zinc oxid is reduced, the hydrocarbonbeing split up into carbon monoxid and hydrogen, analogous to thesplitting up of hydrocarbons by superheated steam. Hethane gives in thisreaction one molecule of carbonmonoxid and four atoms of hydrogen, (CHand ethane in the same reaction gives two molecules of carbonmonoxid andsix atoms of hydrogen, (CzI'It.)

The difference between the present process and the one described in myprevious patent is that with the patented process the watergas i'. 0.,carbon monoxicl and hydrogenis the only reducing agent, whereas with thepresent process the hydrocarbons perform a reducing action partly bybeing split up into carbon monoxid and hydrogen and partly by these twosubstances formed by their destruc- Equation No. 1 shows the splittingup of the hydrocarbon and is readily understood. In equation N o. Q-thereduction is continued and the equation with increasing temperature isgoing to the right, since the reaction is absorbing heat to the rightside. The reaction is easy, owing to the great difierence in the heatformation?l. a, (ZnO eighty five thousand calories minus (H20:)fifty-eight thousand calories equal twenty-seven thousand calories. Thewater formed in equation No. 2 is partly reduced by methane, which isunderstood from equation No. 3' and partly by the equation No. 3. Theequation No. 3* is going entirely to the. right side until theconcentration of CO2 becomes so great as 'to correspond to theequilibrium at this temperature. The calculation shows that for eachgiven temperature in the equilibrium the proportion of the partialpressures must be constant, as will be understood by persons familiarWith chemical dynamics. The reaction indicated by equation No. 2 gives,therefore, CH2() I K, while the reaction indicated in a CHzCCOz Iequation N o. 3 gives K (C meaning concentration.) Therefore I .place ifinstead of using methane or natural gas any other gaseous or gasifiedhydrocarbon or mixture of hydrocarbons is used.

By this process any natural or roasted material containing zinc oxid,zinc carbonate, zinc silicate, or zinc hydrate, or mixtures of the samecan be reduced-such, for example, as roasted blende of any grade,roasted galena blende, franklinite, Willemite, Zincite, calamin,smithsonite, hydrozincite, &c.

My present process is carried into, effect in the same way as mywater-gas process described in my patent before referredto. Thehydrocarbons are heated in ovens or recuperators and injected into thefurnace or reducingchamber containing the charge. The cooled zinc-vaporsare condensed in a suitable apparatus for the purpose.

It will be understood, of course, that In process can be carried out inconnection with the condensation of zinc-vapors obtained by any otherprocess or reaction-as, for example, by heating blende with iron or ironsilicate. It will also be understood that zincvapors prepared in ablast-furnace, as I have described, can, if desired, be oxidized by acurrent of air to produce pure oxid of zinc instead of being condensedto spelter in a condensation apparatus.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is as follows:

1. An improved process for reducing zinc oxidic ores, which consists insubjecting the material to the reducing effect of hydrocarbons ingaseous or gasified form heated previously to entrance in thereducing-chamber, substantially as set forth.

2. An improved process for making spelter from zinc oxidic ores, whichconsists in subjecting the material to the reducing effect of gaseous orgasified hydrocarbons heated previously to entrance in thereducing-chamber, and in cooling the resulting zinc-vapors in anatmosphere of such gas, substantially as and for the purposes set forth.

3. An improved process for making spelter from zinc oxidic ores orzincic materials, which consists in subjecting a mixture of suchmaterial and coal to the reducing efl ect of gaseous or gasifiedhydrocarbons heated previously to entrance in the reducing-chamber, andin cooling the resulting zinc-vapors in an atmosphere of such gas,substantially as and for the purposes set forth.

a. An improved process for reducing Zinc oxidic ores, which consists insubjecting the material to the reducing effect of natural gas, the saidgas being highly heated previous to entrance in the reducing-chamber,substantially as and for the purposes set forth.

5. An improved process for reducing Zinc oxidic ores, which consists insubjecting the material to the reducing efiect of natural gas, the saidgas being highly heated previous to entrance in the reducing-chamber,and in cooling the resulting zinc-vapors in an atmosphere of such gas,substantially as and for the purposes set forth.

6. An improved process for reducing zinc oxidic ores, which consists insubjecting the material tothe reducing effect of a gas composed almostentirely of methane, the said gas being highly heated previous toentrance in the reducing-chamber, substantially as and for the purposesset forth.

7. An improved process for reducing zinc oxidic ores, which consists insubjecting the material to the reducing effect of a gas composed almostentirely of methane, the said gas being highly heated previous toentrance in the reducing-chamber, and in cooling the resultingzinc-vapors in an atmosphere of such gas, substantially as and for thepurposes set forth.

8. An improved process for reducing zinc oxidic ores, which consists insubjecting the material to the reducing effect of a hydrocarbon, in agaseous or gasified condition, the said hydrocarbon containing not morethan fifteen per cent. of nitrogen, the said hydrocarbon bcing highlyheated previous to entrance in the reducing-chamber, substantially asand for the purposes set forth.

9. An improved process for reducing zinc oXidic ores, which consists insubjecting the material to thereducingeffect of a hydrocarbon in agaseous or gasified condition, the said hydrocarbon containing not morethan fifteen per cent. of nitrogen, the said hydrocarbon being highlyheated previous to entrance in the reducing-chamber, and in cooling theresulting zinc-vapors in an atmosphere of such hydrocarbon,substantially as and for the purposes set forth.

10. An improved process for making spelter, which consists in subjectingzinc-containing materials to the reducing effect of a mixtu re ofgaseous or gasified hydrocarbons and water-gas heated previously toentrance in the reducing-chamber, substantially as and for the purposesset forth.

11. An improved process for making spelter from zinc oxidic ores orzincic material, which consists in reducing such material within achamber solely by the action of heated gaseous or gasiiied hydrocarbonsintroduced within the chamber in a heated state, and in cooling theresulting zinc-vapors in an atmosphere of such gas, substantially as andfor the purposes set forth.

12. An improved process for making spelter from zinc oxidic ores, whichconsists in subjecting the material to the reducing effect of gaseous orgasilied hydrocarbons heated previously to entrance in thereducing-chamber, and in cooling the resulting zinc-vapors in anatmosphere of such gas, or carbon monoxid formed by its destruction,substantially as and for the purposes set forth.

13. An improved process for making spelter from Zinc oxidic ores orzincic material, which consists in reducing such material within achamber solely by the action of heated gaseous or gasified hydrocarbonsinjected within the chamber in a heated state, and in cooling theresulting zinc-Vapors in an atmosphere of such gas, or carbon monoxidformed by its destruction, substantially as and for the purposes setforth.

This specification signed and witnessed this 7th day of January, 1903.

OSKAR N AGEL.

W'itnesses:

FRANK L. DYER, J NO. RoB'r. Tinmon.

